| Home | E-Submission | Sitemap | Contact Us |  
Soonchunhyang Med Sci > Volume 28(2); 2022 > Article
Kim and Lee: Removal of Lumbar Synovial Cyst Using Biportal Endoscopic Surgery: A Case Report


The synovial cyst of the spine may be caused by degenerative changes or instability of the spine. The most common site of spinal synovial cyst is the lumbar spine. If conservative management is failed, the operation must be considered. So far, microscopic cyst removal has been considered a treatment of choice. Recently, biportal endoscopic surgery is now becoming increasingly common in spine surgery and has the advantage of minimizing damage to related structures such as muscle, bone, and nerve. There was a case in which the synovial cyst of the L4–5 level was successfully removed through a biportal endoscopic surgery, so we would like to report it with a literature review.


The synovial cyst of the spine may be caused by degenerative changes or instability of the spine [13]. The most common site of spinal synovial cysts is the lumbar spine [4]. Large synovial cysts can compress the nerve root and thecal sac, and then this compression can cause radiating pain in the lower extremities and back pain [2]. Unless conservative management such as aspiration and corticosteroid injection were effective, surgical resection of synovial cysts should be considered [5]. Microscopic cystic removal has become a widely used surgical method so far [6]. Recently, biportal endoscopic spine surgery has been gradually used for discectomy, decompression, and fusion surgery [7]. We have also removed the spine synovial cyst using biportal endoscopic surgery, which we would like to report together with a literature review.


A 74-year-old male patient suffered from low back pain with right radiating pain from 1 month ago. He squatted down and worked in the fields before developing the symptoms. At first, other hospital gave him medication suitable for the symptoms, but the pain did not decrease and rather weakness in the right lower extremity occurred.
On the physical examination, the power of ankle dorsiflexion on the right side was grade III and steppage gait was observed while walking. In simple dynamic radiographs, degenerative spondylolisthesis of grade I was found (Fig. 1). In magnetic resonance images, it was confirmed that a synovial cyst was present on the right side of L4–5 with facet effusion (Fig. 2).
The authors performed an ipsilateral biportal endoscopic surgery. The patient was placed in a prone position with general anesthesia. Two transverse skin incisions were made 2 cm apart at the margin of the interlaminar space under the C-arm guide. Subcutaneous fascia and muscles were split using a dilator, and then a 0° arthroscope was inserted. About 1 mm of partial laminectomy was performed at the right L4 distal part and L5 proximal part, and then partial flavectomy was performed. The synovial cyst was found and we easily resected the cyst without facet injury (Fig. 3). The pathology of the cyst was confirmed as a synovial cyst.
In postoperative magnetic resonance imaging, the synovial cyst pressing on the dura was no longer identified (Fig. 4), the symptoms improved, and the foot drop returned to normal a week after surgery. There was no pain or recurrence of the cyst after 1 year of surgery.
The patient provided written informed consent for the publication of clinical details and images.


Spinal synovial cysts caused by degenerative changes or instability occur in old people, especially older than 70 years old [8]. Among the synovial cysts in the spine, about 10% cause symptoms such as low back pain or radiating pain. Almost synovial cysts are located in the lumbar spine [4]. Since the L4–5 level is the most flexible segment in the spine, degenerative spondylolisthesis is easily generated in the area, and synovial cysts could be easily generated accordingly [9].
If symptoms appear due to a synovial cyst in the spine, conservative management should be attempted first. Conservative treatment includes cyst aspiration, which has a very high failure rate [9]. Microscopic surgery is a recent treatment of choice for symptomatic spinal synovial cysts [6]. But the ipsilateral microscopic approach involves partial laminotomy with medial facetectomy, it may induce postoperative segmental instability [10]. Recently, biportal endoscopic technique in the spine is a minimally invasive surgical modality and has been used gradually and widely [7]. As a biportal endoscopic spine surgery provides real-time magnification images of the surgical field through the endoscope, small surgical dissection can provide a sufficient surgical field to perform thorough and fine lumbar surgery [11].
In this case, complete removal of juxtafacet cyst was performed via an ipsilateral interlaminar approach and iatrogenic facet violation was avoided. As a result, postoperative instability in the facet joins has not occurred, and the degenerative spondylolisthesis did not worsen, resulting in no further radiating pain and recurrent synovial cysts. This is reported along with a review of the literature review.


This work was supported by the Soonchunhyang University Research Fund.


No potential conflict of interest relevant to this article was reported.

Fig. 1
Simple dynamic radiographs revealed the grade I degenerative spondylolisthesis at L4–5. (A) Extension (EXT). (B) Flexion (FLEX).
Fig. 2
In the magnetic resonance imaging, a synovial cyst appeared on the right side of the L4–5 and compressed the thecal sac (arrow). (A) Sagittal. (B) Axial. (C) Coronal.
Fig. 3
(A) A synovial cyst compressed the right side of the epidural using biportal endoscope (arrows). (B) Retracting the dural sac, the synovial cyst was well confirmed (arrows). (C) The synovial cyst was removed.
Fig. 4
In postoperative magnetic resonance images, it was confirmed that the synovial cyst was completely removed without damage to the right facet joint. (A) Sagittal. (B) Axial.


1. Bydon A, Xu R, Parker SL, McGirt MJ, Bydon M, Gokaslan ZL, et al. Recurrent back and leg pain and cyst reformation after surgical resection of spinal synovial cysts: systematic review of reported postoperative outcomes. Spine J 2010;10: 820-6.
crossref pmid
2. Khan AM, Girardi F. Spinal lumbar synovial cysts: diagnosis and management challenge. Eur Spine J 2006;15: 1176-82.
crossref pmid pmc
3. Sabo RA, Tracy PT, Weinger JM. A series of 60 juxtafacet cysts: clinical presentation, the role of spinal instability, and treatment. J Neurosurg 1996;85: 560-5.
crossref pmid
4. Bruder M, Cattani A, Gessler F, Droste C, Setzer M, Seifert V, et al. Synovial cysts of the spine: long-term follow-up after surgical treatment of 141 cases in a single-center series and comprehensive literature review of 2900 degenerative spinal cysts. J Neurosurg Spine 2017;27: 256-67.
crossref pmid
5. Sukkarieh HG, Hitchon PW, Awe O, Noeller J. Minimally invasive resection of lumbar intraspinal synovial cysts via a contralateral approach: review of 13 cases. J Neurosurg Spine 2015;23: 444-50.
crossref pmid
6. Scholz C, Hubbe U, Kogias E, Roelz R, Klingler JH. Microsurgical resection of juxtafacet cysts without concomitant fusion: long-term follow-up of 74 patients. Clin Neurol Neurosurg 2017;153: 35-40.
crossref pmid
7. Choi DJ, Kim JE. Efficacy of biportal endoscopic spine surgery for lumbar spinal stenosis. Clin Orthop Surg 2019;11: 82-8.
crossref pmid pmc
8. Doyle AJ, Merrilees M. Synovial cysts of the lumbar facet joints in a symptomatic population: prevalence on magnetic resonance imaging. Spine (Phila Pa 1976) 2004;29: 874-8.
9. Shah RV, Lutz GE. Lumbar intraspinal synovial cysts: conservative management and review of the world’s literature. Spine J 2003;3: 479-88.
crossref pmid
10. Themistoklis KM, Papasilekas TI, Boviatsis KA, Giakoumettis DA, Vlachakis EN, Themistocleous MS, et al. Spinal synovial cysts: a case series and current treatment options. J Clin Neurosci 2018;57: 173-7.
crossref pmid
11. Kang MS, Hwang JH, Choi DJ, Chung HJ, Lee JH, Kim HN, et al. Clinical outcome of biportal endoscopic revisional lumbar discectomy for recurrent lumbar disc herniation. J Orthop Surg Res 2020;15: 557.
crossref pmid pmc
Editorial Office
Soonchunhyang Medical Research Institute.
31 Soonchunhyang6-gil, Dongnam-gu, Cheonan, Choongnam, 31151, Korea
Tel : +82-41-570-2475      E-mail: chojh@sch.ac.kr
About |  Browse Articles |  Current Issue |  For Authors and Reviewers
Copyright © 2024 by Soonchunhyang Medical Research Institute.                Developed in M2PI